The Act of Union is a name given to several acts passed by the English, Scottish and British parliaments from 1536 onwards. Among those:

The term "act of union" is also used as a euphemism for sexual intercourse.

This is a disambiguation page; that is, one that just points to other pages that might otherwise have the same name. If you followed a link here, you might want to go back and fix that link to point to the appropriate specific page.